Weber 6A14 build not putting out

[MickeyB]

I'm getting a normal low hum sound from the speaker with the volume at 0. As soon as I turn the volume up I get a pop and it goes dead quiet until 10 and then it pops again and the hum is back. When it pops I can hear the reverb working and when its on 0 and turn the vibrato on, i can hear that working in the hum. But I can not get any sound from the guitar at any volume level. I have 316v at the cathodes and set the bias to 28mv. I've checked and rechecked every solder joint and wiring in this and am now asking for any suggestions on what to look for causing the problem.

[Enzo]

Did it ever work right, or is this how it started its life? The difference is that if it used to work we can assume the circuit was right an something failed or came loose. If it have not ever worked right so far, then we cannot make those operating assumptions.

My inclination is to think you have either mounted an electrolytic cap backwards, or mounted two parts in each others position, or have a wrong part. For example a 470 ohm resistor in place of a 470k resistor. Another thought is a ground connection left out.

[MickeyB]

Its a new build that I just completed and fired up for the first time. I did double check every cap before I soldered them down and made sure all arrows point to ground. I'll check the resistors to see if I did put in a wrong value and check ground connections.

[Jag]

The 50uf/150v cap in the bias supply should NOT have the - to ground. It is part of the negative voltage supply for the bias and should have + to ground. Putting it in the wrong way around will probably fry it and you will get hum and unstable bias. I mention this because you said, "all arrows point to ground".

If that cap is backwards/blown, you'd still get some sort of signal output so, there are probably additional issues.

[MickeyB]

Sorry, all but that one. I do have it pos to ground. The rest are correct. I'll start going through all the resistors and see if I have any of those wrong.

[MickeyB]

Checked everything to the schem. Checked all the resistor values. Checked all the caps + -. Checked every solder connection. Still the same pop and no sound. While checking voltages, V4 at pin 1, the voltage goes from 110v to 258v and then back down. Is that suppose to go up and down like that? I switched tubes and it did the same thing. None of the other voltages go up and down like that.

[Enzo]

Does the tremolo speed control affect how fast this happens? I bet it does. Pin1 of V4 is the plate of the trem oscillator tube. The tremolo signal is there and is a pretty large voltage signal.

Wait, you have "316 volts at the cathodes?" What does that mean? What cathodes? What tubes? DO you mean plates? If you have 316v at any cathode, the tube has an open cathode circuit.

Look at pin 8 of each power tube socket. Is it grounded? Is there like zero ohms to ground?

[MickeyB]

The tremelo control does not change it. Sorry, I meant plate voltage. Pin 8 goes to bias pin outs for measuring then to 1 ohm 1% resistors to ground. I ran it idle for a few minutes, poked around with chopstick, nothing. So I did voltage measurements. Their attached in a excel file. Something isnt right, but I can't figure out what the cause is. Do these readings explain anything?

[Normybaby]

Check your tone/coupling caps for DC leakage. Pin 7 V1 reading seems high

[MickeyB]

Well I found out that I do get sound out of it. But only with the volume on 10. Nothing from 1 to 9. With it all the way up, I checked the other pots and the treble squealed when I turned it up, the bass worked fine and so did the reverb and vibrato. Their all wired per the layout shown. All connections are good. Do I have a pot wired wrong?

[MickeyB]

I saw another thread where someone had trouble due to the reverb. So for yucks I unhooked the reverb transformer to see if it would make a difference and now the volume works fine. Bad transformer??